Known brazing processes include a vacuum cleaning cycle in a vacuum chamber to remove surface oxides from a base material of an article. The cleaning cycle enables wetting of a surface of the base material that is to be brazed. Once cleaned, the article is removed from the vacuum chamber and a braze paste, pre-sintered preform, or other similar braze material is applied to the surface. The article is then placed back into the vacuum chamber.
These brazing processes suffer from several drawbacks. For example, once the article is removed from the vacuum chamber, oxides form or reform. These processes have long been unable to completely prevent oxides from forming or reforming. Such forming and reforming of oxides is especially prevalent in complex shapes, cavities, fissures, or other regions that are difficult to reach or view. In addition, such processes involve multiple cycles to complete a brazing process, thereby extending the overall duration of the brazing process.
Alternatively, multiple vacuum chambers are used. Multiple cycles, extended durations for brazing processes, and multiple chambers can result in undesirably high operational and/or capital costs.
Known processes attempt to reduce oxide formation and reformation. For example, mechanical cleaning, such as with carbide burr, can remove some oxides, especially surface oxides. However, mechanical cleaning is unable to remove all oxides, such as oxides that are not on the surface, can be inconsistent, and can form dust. Ultrasonic cleaning can remove dirt and grease. However, ultrasonic cleaning does not remove all surface oxides. Nickel plating can be used to improve wetting on material that quickly form or reform oxides, but adds substantial costs and cannot be applied in all circumstances.
A brazing process, a braze assembly, and a brazed article not suffering from one or more of the above drawbacks would be desirable in the art.